To his long list of creative credentials (actor, comedian, songwriter, playwright, author and screenwriter), Steve Martin can now add curator -- of the Hammer Museum's "The Idea of North," the first major U.S. exhibition of paintings by Canadian Group of Seven artist Lawren Harris.

Martin, 70, has been collecting art for nearly 50 years. Together with his equally art-obsessed wife, Anne Stringfield (with whom he has a 2-year-old daughter), he continually adds to a collection that includes seminal works by Edward Hopper, Willem de Kooning, David Hockney,John Currin and Eric Fischl, a longtime friend. The actor acquired the first of his three pieces by Harris about 10 years ago, and during a 2012 din­ner party at Martin's home, one of the paintings caught the eye of Hammer director Ann Philbin. "Who's that?" Philbin asked.

"In that moment, I realized I had a secret wish," Martin recalls. "That Lawren Harris be better known in America." A few months later, Philbin popped the question: Would Martin help curate a Harris show? "My response surprised me: Yes," says the actor. "Harris is the only artist I could conceive of getting involved with as a curator, and this is a time my celebrity face might actually do the world some good."

347908 49: Steve Martin attends the Vanity Fair Oscar party March 21, 1999 in Los Angeles, CA. The party, organized by Vanity Fair magazine, is held at Morton''s restaurant and is considered one of the most important venues for the celebrities after the awards ceremony. (Photo by Barry King/Liaison)

Steve Martin and Goldie Hawn with stunned faces at hotel door in a scene from the film 'The Out-Of-Towners', 1999. (Photo by Paramount/Getty Images)

Steve Martin holds a phone in a scene from the film 'Mixed Nuts', 1994. (Photo by Metro-Goldwyn-Mayer/Getty Images)

DETROIT, MI - JUNE 05: Steve Martin performs with the Steep Canyon Rangers at The Soundboard, Motor City Casino on June 5, 2014 in Detroit, Michigan. (Photo by Paul Warner/WireImage)

LOS ANGELES, CA - MARCH 22: Actor Steve Martin attends the Backstage At The Geffen annual fundraiser held at Geffen Playhouse on March 22, 2014 in Los Angeles, California. (Photo by Tommaso Boddi/WireImage)

UNITED STATES - MAY 03: Steve Martin (left), Candice Bergen and Harrison Ford get together at Avery Fisher Hall for the Film Society of Lincoln Center's gala tribute to Mike Nichols. (Photo by Richard Corkery/NY Daily News Archive via Getty Images)

Dan Aykroyd and Steve Martin interacting in a scene from the film 'Sgt. Bilko', 1996. (Photo by Universal Pictures/Getty Images)

Harris' paintings -- buoyant, otherworldly landscapes of snow-covered mountains, the most significant of which were created by the late artist in the 1920s and '30s -- "transmit a lot of power or serenity, depending on the picture," Martin says. "Harris really took out every living thing and painted almost ideal pictures of the North. He abstracted them somehow."

Martin worked with Hammer cura­tor Cynthia Burlingham and Art Gallery of Ontario's Andrew Hunter for two years to select and gather the 30-plus paintings for the show, which opens Oct. 11. Asked how deeply he was involved, Martin replies, "I think I went all the way." He flew to different museums across Canada and met with private collectors, often traveling with Burlingham or Hunter, "so whatever I lack in experience, they made up for." (Hunter recalls the stupefied looks of the truck-stop waitresses when he and Martin stopped for panini outside Toronto: "This is the guy I saw pack Toronto's Maple Leaf Gardens with over 10,000 people for a stand-up show when I was in high school.") Says Martin, "We got almost every picture we wanted, and when we didn't, it was because it was too fragile to travel."

Martin says the three co-curators used a small model of the exhibition space outfitted with cut-to-scale versions of the paintings to test out different themes and arrangements for the show, which will be installed the week of Oct. 5. "We just want to make Lawren Harris look as good as we possibly can. And it's not hard," he says. "I have such a great love for the pictures that it was a joy from top to bottom. I never considered it work."

As collecting has gained cachet, Martin dismisses the notion that younger Hollywood aficionados are following his lead. "I don't think Leonardo DiCaprio or Owen Wilson were at all influenced by me -- they were influenced by the power of the current art scene and the great artworks being made," he says. "It's a completely natural place for them to be. Contemporary art is very accessible to contemporary people — to younger people. It's their art."

But don't look for the actor's passion to extend to a Broad-style museum of his own. "I don't have the depth or the wealth -- you have to have thousands of paintings," he says. "When I've bought a new painting, I sometimes had to sell one in order to get it. So I have moved through a lot of paintings." And few have moved him as deeply as Harris'. "I can't wait for the public to see this work -- art people, all kinds of people. Even though some of them were painted 60, 85, 95 years ago, they are going to be seen afresh."